For a budget speaker for an mp3 player, this does what it promises to do, but not really anything more. It's very simple to unbox and set up. To power it up, simply pop in 4 AA batteries or plug it into your computer via the USB cable supplied. The other wire, which is discreetly housed inside the speaker, then plugs into the headphone socket of your mp3 player.
In terms of aesthetics, the speaker looks elegant and the blue LED on/off light on the top is pleasing (although the glowing words "Amazon Basics" less so). It does feel 'plasticy', but not cheap per se, and besides, what do you expect at this price point. The sound is fine too, but not special enough to feel like its worth using. In other words, it feels like far less hassle to just listen to my iPhone 5 via its own speakers with the volume turned up, rather than wiring this thing in every time. That said, other mp3 players or older phones with inferior speakers to, say, an iPhone 5 probably wouldn't measure up, making this speaker seem a more worthwhile proposition.
Basically, if your mp3 player or phone doesn't produce good enough sound through its own speakers and you want a good value solution to that problem, this will see you alright. If your mp3 player or phone already produces decent sound though, you don't really need this.